Studio Reference Amplifier

Hello Viki_V2

How did you do this? If you increase the print size, thus the other components still fit? what about the IC pins, are they still ok?

Regards,
MACD:eek::eek::eek:

Most of the times. printers print the image a bit smaller than actual size, Unless this is done through special softwares like Photoshop and coreldraw.

increasing size by3.5 mm does not make huge difference on the overall size of pcb. Components fit properly. If you want increase only on sides, not on top and bottom.

Good luck
 
@Mamak, looking at the above photo's I would say operating voltage for this amplifier would be +/- 50v to say 70v and adding more o/p's will help share the voltage/current better.

power wise may be 140w@8 or more and 200/300w@4 ohms.. plus if it's bridged even more.
some power out check's would have to done via scope and sine injection...
 
@Mamak, looking at the above photo's I would say operating voltage for this amplifier would be +/- 50v to say 70v and adding more o/p's will help share the voltage/current better.

power wise may be 140w@8 or more and 200/300w@4 ohms.. plus if it's bridged even more.
some power out check's would have to done via scope and sine injection...

Out put is 200 watts@8ohms with +/- 75v
275 watts @4ohms with +/-65v
 
Hello Sir Apex,

I have just completed my first channel of your SR200 design. I must admit, this is one good amplifier.....the sound is one of the best that I have heard in a long time. Bass is good, mids and high very clear. I connected input straight from CD player, no preamp, and I must say, this is one excellent amp. Here is some pictures of my first channel. Planning to build second channel today. :D:D:D

Thank you Alexx mm for a wonderful PCB design. It is easy to build and work first time. Thank you very much. :D:D:D Just one small request, as you can see from my pictures I only have two power transistors populated. I cannot fit a third one in this PCB. Space is a bit to small for 3 outputs. Can you modify this PCB by increasing the spacing between the power transistors, as I would like to populate 3 power transistors. ;););)

One Question Sir Apex. What is the maximum voltage for 2 power transistors in output?

Once again, thank you very much Apex and Alex mm for a wonderful design.:D:D:D

Regards
MACD:):):)

Nice work, I suggest to use SanKen 2SA1294/2SC3263 and you can fit 3 pairs on this pcb, use transformer with 2x50-55v AC voltage.
Regards
 
Viki_v2.

Thanks for the pointing to the (post 35).. I've looked back and seen some of the posting of this amplifier very nice... yes 200w sounds about right for that given supply line..I will at some point under take the build..

In my files I have a studio 350 power amplifier design using 70 +/- supply rail's and giving rms o/p of 350w in to 4ohms and 200w in to 8 ohms plus this design using 8 o/p devices a bit over kill..4 2sc5200's and it's counter part... the only down side was no s/c limiter so you see if the o/p was shorted bang went the o/p trannies.. I must say I'm fan of adding this type of protection circuity to amplifier's if they don't have them.. and not for getting a good fast acting speaker delay/protection unit and as we don't want are pride and joy speaker's getting fried due to amplifier going dc..not good...

I do like to see well built designs getting high rating's and this amplifier is getting plenty of high rating.. thumbs up to the designer.
 
macd nice built amplifier , yes it's my mistake regarding size of output transistors . I hoppe now will be the correct one .It was designed for MJL 1302 and MJL 3281 with TO3P case (I have 20 pices ON SEMI) ;) :) :D
Alex mm not Alexx mm !
L.E. Sorry , value for emiter resistor 0.33 ohm not 0.68 , please correct .
 

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RE Cap Value....

C1 is 10uF/50V, and you use 1uF/250V, try to increase value of C1 (2,2uF 3,3uF 4,7uF 6,8uF... is available)
Regards

Hello Apex,

Yes I know, I tried to get 10uF/63V but supplier was out of stock. I will get the correct value and replace C1. I will even try to increase value as you suggested and will give feedback on my listening experience. I listen to your amp yesterday for about a hour, and I must confess, it is excellent. :D:D:D Almost complete with second channel. Will post some pics when completed.

Can I use this PSU with ±65V supply? If yes, what changes do I need to make? :p:p:p

Regards
MACD
 

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  • APEX F100PSU PCB.jpg
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RE PCB...

macd nice built amplifier , yes it's my mistake regarding size of output transistors . I hoppe now will be the correct one .It was designed for MJL 1302 and MJL 3281 with TO3P case (I have 20 pices ON SEMI) ;) :) :D
Alex mm not Alexx mm !
L.E. Sorry , value for emiter resistor 0.33 ohm not 0.68 , please correct .

Hello Alex mm,

Sorry for my wrong spelling. Thank you very much for this updated PCB. I tried to get MJL transistors but local supplies does not stock them. I will use this new version PCB in future builds.

Once again, thank you very much for your PCB layout.:D:D:D

Regards,
MACD:):):)
 
Hello Apex,

Yes I know, I tried to get 10uF/63V but supplier was out of stock. I will get the correct value and replace C1. I will even try to increase value as you suggested and will give feedback on my listening experience. I listen to your amp yesterday for about a hour, and I must confess, it is excellent. :D:D:D Almost complete with second channel. Will post some pics when completed.

Can I use this PSU with ±65V supply? If yes, what changes do I need to make? :p:p:p

Regards
MACD

You can use PSU from 'DC Servo Mosfet Amp' with 10000uF/80V and 1k5/5W instead 1k2/5W.
Do you compare sound of SR200 with other amps?
You can use SanKen 2SA1294/2SC3263 or you can find some other outputs in TOP3 or TO247 case.
Only with stereo amp you can feel complete sound quality of SR200.
Regards
 
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RE PSU....

You can use PSU from 'DC Servo Mosfet Amp' with 10000uF/80V and 1k5/5W instead 1k2/5W.
Do you compare sound of SR200 with other amps?
You can use SanKen 2SA1294/2SC3263 or you can find some other outputs in TOP3 or TO247 case.
Only with stereo amp you can feel complete sound quality of SR200.
Regards

Hello Apex,

Yes, I have a commercial PIONEER amp, a DX ST and a DX supercharge, and also have a mosfet amp as well, but I like SR200 sound the most. Speakers are small bookshelf type. Will connect with proper speakers (15" inch) this weekend.:p:p:p

Can I use this PSU for SR200 amp. I know there is no PRO pin on SR200, but will soft start, switch on delay and DC cutout still work? If yes, what changes do I have to make to work of ±65V?

Regards,
MACD:D:D:D
 

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  • APEX HV350 PSU.jpg
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Hello Apex,

Yes, I have a commercial PIONEER amp, a DX ST and a DX supercharge, and also have a mosfet amp as well, but I like SR200 sound the most. Speakers are small bookshelf type. Will connect with proper speakers (15" inch) this weekend.:p:p:p

Can I use this PSU for SR200 amp. I know there is no PRO pin on SR200, but will soft start, switch on delay and DC cutout still work? If yes, what changes do I have to make to work of ±65V?

Regards,
MACD:D:D:D

You can use this PSU without changes, protect circuit use separate 20V AC suply, and amp PSU voltage can be change to +/-65V. I suggest to add overload protect circuit from HV350, and you have 'pro' from SR200.
Regards